First Ragweed of Season Sighted in New Jersey and New York

NEW BRUNSWICK, N.J. – Ragweed season has begun in the New York-New Jersey metropolitan area with the first sighting today

by Dr. Leonard Bielory, a specialist in allergy and immunology with the Department of Environmental Sciences at the Rutgers School of Environmental and Biological Sciences.

Bielory, certified by the American Academy of Allergy, Asthma and Immunology National Allergy Bureau as a pollen counting station, says that sightings of ragweed generally occur towards the end of the third week of August.

“The earlier sighting is consistent with our findings that climate change may be affecting pollen release and earlier development of allergies,” said Bielory.

Bielory is principal investigator on a long-term U.S. Environmental Protection Agency grant to study the potential impact of climate change on the human population, especially allergic airway disease, and what to expect over the course of the next 50 years.

A changing climate means allergy-causing ragweed pollen has a longer season that extends further north than it did just 16 years ago. In New Jersey, the season appears to have longer exposure time due to earlier pollination and longer release days.

Three out of four Americans who have allergies are allergic to ragweed pollen, which causes hay fever. Allergies associated with ragweed pollen costs about $21 billion a year in the United States.

“Allergies that have been minor in the past are going to increase and become more of a clinical problem that may also impact patients with asthma,” said Bielory.

Three out of four Americans who have allergies are allergic to ragweed
pollen, which causes hay fever. Allergies associated with ragweed pollen
costs about $21 billion a year in the U.S

According to a study published in February in the Proceedings of the National Academy of Sciences, experts found that ragweed pollen season lasted as much as 27 days longer in 2009 than it did in 1995 with increasing range the further north one got. The result is a more dramatic change in the length of the pollen season, says Bielory.

At one time this was hypothesized and modeled as a possibility, “but it is a reality; this is affecting patients now,” said Bielory.

As global average temperatures have warmed, the first frost has been delayed, especially at higher latitudes, which means a longer season for ragweed.“Because warming is greater at these high latitudes, the length of the season has been more pronounced,” he added.

The report states that the ragweed season actually shrank by four days between 1995 and 2009 in Texas while further north it was noted to be 11 days longer in Nebraska; 16 days longer in Minnesota; and 27 days longer in Saskatchewan, Canada.

In New Jersey, the season appears to have grown longer over the past 20 years, but not as prolonged as the differences noted in Canada. The shift is likely to have an impact on the diagnosis of allergies coinciding with the flu season.

“Primary care physicians may under-diagnose and under-treat allergies since they’d be unfamiliar with the change in the allergy season and may require the assistance of an allergist to confirm the diagnosis and prescribe the most effective treatment for their patients.

Ragweed is not the only pollen season affected by changing climate. The wide-ranging EPA study will also be evaluating the impact on tree and grass pollen seasons in the early and late spring.